An Overview of Nutrition Chapter 1

An Overview of Nutrition  Nutrition 

The science of the nutrients in foods and their actions in the body.

 Diet 

The foods and beverages a person consumes

Food Choices  Choices

are personal, behavioral or social

 Personal 

preference

Sweet, salty, spicy

 Habit  Ethnic

Heritage or Regional Cuisine  Social Interactions  Availability, convenience, economy 

Accessible, easy to prepare, affordable

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Food Choices  Positive

and negative associations  Emotional comfort 

Boredom, depression, anxiety

 Values 

Religious beliefs, environmental concerns

 Body

weight and image

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Food Choices  Nutrition  Functional  Provide



and health benefits

foods

health benefits beyond their nutrient contributions  Ex. Whole foods, fortified foods Phytochemicals  Non-nutrient compounds found in plant derived foods that have biological activity in the body

The Nutrients  Nutrients

the Body

in Food and in

 Nutrient

–chemical substances obtained from food and used in the body to provide energy, structure, growth, maintenance and repair of body tissues

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The Nutrients in Food and in the Body Composition Water

of foods

Carbohydrate,

protein, lipid Vitamins, minerals Non-nutrients  Fiber,

phytochemicals, pigments, additives

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Body Composition of HealthyWeight Men & Women

The Nutrients Chemical

composition of

nutrients Inorganic – not containing carbon (minerals and water) Organic nutrients – contain carbon (carbohydrate, protein, lipids, and vitamins)

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Elements in the Six Classes of Nutrients

The Nutrients Essential Nutrient A nutrient that the body does not make, or makes in insufficient amounts to meet the body’s needs; These must be supplied by food

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Energy-Yielding Nutrients Macronutrients

Energy-Yielding Nutrients  Energy-

the capacity to do work; food energy is chemical energy  Calorie – unit by which energy is measured. Food energy is measured in kilocalories.  1000 calories equal 1 kilocalorie  The scientific use of the term kcalorie is the same as the popular use of the term calorie

Energy is measured in kcalories (commonly called calorie”)

Calorie- unit of energy so small that an apple provides tens of thousands of them. To make it easy to calculate, energy is expressed in 1000 calorie metric units known as kilocalories, which we shorten to kcalories or calories.

Energy from Food  The

amount of energy or kcalories a food provides depends on the amount of:



Carbohydrate (4 kcalories/gram) Protein (4 kcalories/gram) Fat (9 kcalories/gram)



Alcohol (7kcalories/gram)

 

Energy Density

Calculating Energy from Food 1

slice of bread with 1 TBSP of peanut butter contains 16 grams of carbohydrate, 7 grams of protein, and 9 grams of fat. 16 grams carb X 4 kcalories per gram = 64 kcalories  7 grams protein X 4 kcalories per gram = 28 kcalories  9 grams of fat X 9 kcalories per gram = 81 kcalories Total = 173 kcalories What % is from fat? 81 fat kcalories÷173 total kcalories = 0.47 .47 X 100 = 47% 

Energy-Yielding Nutrients  Energy  

Energy for activity, brain function, body functions Stored energy

 Other 

in the body

roles of energy-yielding nutrients

Building tissues, providing structure, regulating activities

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Vitamins- Micronutrients  Organic  Not

energy-yielding  Essential  Water-soluble and fat-soluble  Vulnerable to destruction  Each of the 13 different vitamins has its own specific role in the body  Almost every bodily action requires assistance from vitamins

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Minerals-Micronutrients  Inorganic  Not

energy-yielding  Essential  Indestructible  Stable in cooked foods

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Water  Provides

the environment in which nearly all the body’s activities are conducted.  Inorganic  Not energy-yielding  Essential

The Science of Nutrition  The

study of nutrients and other substances in foods and the body’s handling of them.  The science of nutrition depends on biology, biochemistry, and physiology

The Scientific Method

Conducting Research  Use 

of scientific method

Systematic process for conducting research

 Research 

studies

Controls  Randomization

  

Sample size Placebos Double-blind experiments

Nutrition Research

Nutrition Research

Publishing Research  Peer 

review

Research has validity

 Findings 

are preliminary when published

Not meaningful by themselves

 Findings

need to be replicated

Dietary Reference Intakes 

A set of standards that define the amounts of energy, nutrients, and other dietary components that best support health.

 Estimated

Average Requirements  Recommended Dietary Allowances  Adequate Intakes  Tolerable Upper Limits

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Dietary Reference Intakes  Estimated

Average Requirements –(EAR) the average amount of a nutrient that is sufficient for half the population  Recommended Dietary Allowance (RDA)- the amount of a nutrient to meet the needs of most healthy people - 98% of the population

EAR and RDA Compared

Establishing Nutrient Recommendations  Adequate

Intake (AI)-

 When

insufficient evidence is present to determine an RDA

 Tolerable  Point

Upper Intake Levels -

where nutrient is likely to be toxic  Helps protect against overconsumption  The maximum amount that appears to be safe for most healthy people

Inaccurate vs. Accurate View of Nutrient Intakes

Estimating Energy Recommendations  Estimated

(EER)

Energy Requirement-

 Average

energy intake that will maintain energy balance  Healthy

body weight  Physical activity

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Energy Recommendations

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Dietary Reference Intakes  Acceptable

Macronutrient Distribution Ranges (AMDR)   

Adequate energy and nutrients Reduce risk of chronic diseases Range  45-65%

kcalories from carbohydrate  20-35% kcalories from fat  10-35% kcalories from protein

Dietary Reference Intakes  Estimates apply to  Needed adjustments  Recommendations

healthy people

– not minimum levels nor optimal levels  Goals intended to be met through diet  Apply to average daily intakes  Each DRI category serves a unique purpose

Nutrition Assessment Malnutrition Undernutrition and  Symptoms of malnutrition Diarrhea  Skin rashes  Fatigue  Others 

overnutrition

Nutrition Assessment of Individuals  Historical

information  Anthropometric data  Physical examination  Laboratory tests

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Nutrition Assessment of Populations  National

nutrition surveys

 Reviews

kinds and amounts of food people eat  Evaluates the people themselves  Used to establish public policy, food assistance programs, regulation of the food supply

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National Health Goals 

Healthy People- National public health initiative that identifies the most significant preventable threats to health and focuses on eliminating them. Overseen by the Department of Health and Human Services (DHHS)

Healthy People 2020 Nutrition & Weight Status Objectives

Healthy People 2020 Nutrition & Weight Status Objectives

Diet and Health Chronic Disease: Slow progression and long duration

Risk Factors for Chronic Diseases  Risk

factor: condition or behavior associated with an increased frequency of a disease, but not proved to be the cause  

Risk factors persist over time Risk factors cluster

Highlight 1 Nutrition Information and Misinformation

HighlightNutrition Misinformation  Not

everything on the Internet is true!!  Determination of the reliability of a website  Anyone can publish anything  No

guarantees of accuracy

 Evaluate  Who,

websites

When, Where, Why, and What?

 May

be high-quality information: National Library of Medicine’s PubMed  May be misleading, incomplete, and inaccurate

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HighlightNutrition Misinformation

Nutrition Information and Misinformation  Nutrition

in the News

 Can

be misleading and contradictory  May report scientific findings prematurely  

Limited understanding Current and controversial

Nutrition Information & Misinformation  Identifying 

Physicians & other health-care professionals  Training



nutrition experts in nutrition is limited

Registered Dietitian (RD)  Degree

and clinical internship  National exam  Maintain up-to-date knowledge 

Dietetic Technician Registered (DTR)

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